Piston head



D. L. MARTYN I PISTON HEAD Filed May 23, 1925 Dec. 6, 1927.

I I Patented a. 6, 1 9 27. I

hem-Gwen.

Ami-1mm marmg zap 92s; sari-.11 no. 32311;

" This invention r lates to heads of ihoriz'ontalqen'gines and inparticular steam locomotives and-liasfor its object thereduo- Figure 1isa'sectional'viewof anordinary locomotive piston head with my'improve-J Figure 45' is a s cnonai' view automatic balancer'. a

Figure ,5"shows a'tongue piece with spring.

' -Referringmore particular-l to the drawings, Figure '1, illustrates apiston; head of atype i in generaluse in locomotive 'practice Iandshowing m'y balaneerg; V

'- Th s balaneer 2,1 has one tundamentalobject, namely to reducefriction,whichi is ac-v complished'bythe actionfo't steam thru it, to

" automatically raise the piston head slightly ofl? the bottom ofcylinder and thus cause the head toffloat on a film of steam.

The 'piston head-1", is dri'lled and tapped at both ends 3 and 4 so thatthe balancer 2 may be screwed into place. H

Packing rings 5 are fitted to .the piston T head by the methods ingeneral use.

The head 1 has a suitable hole 6 drilled in it, at the bottom whichcommunicates with a groove 7, cut approximately half Way roundtheperiphery of the head. Between the packing rings at suitable heightsare inserted two tongue pieces or sliding abutments 8. r

These tongue pieces or abutments are used to prevent neutralization ofthe steam pressure.

r In order that they will be efli'ective they are fitted with a spiralspring 9 Figure 5.

work in and out, so that the springs will at all times keep them closeto the' cylinder walls and so prevent steam getting from the is"confinedfbetweenuthe rings 5 and the tongue-p1eces 8, this places afilm of steam Theeffect is toraise the 'head l and -iuror tensionthey-have is allbwedto work unre- They are made a close fit and yet freeto y when packing rings 5 are in placeand steam is admitted into thehead 1, the steam between the" piston f head" and the cylinder wallsi 1ther, when steam is put into the cylinder-the 60 pressure oii the rings5 is balan'eedbyits aetion, 'that is to say; the steam being 'on' 7 bothsides of the rings 5, whatever spring strained; 1 e

' Referring toF-igure at which Icall'the be ancer 2, it is made of hardmetal; the, outside piece '10; isthreaded at both' ends 'and for ferentdiameters/ convenience in assembling-they are-of dip This piece lO isbored out its entire length and: has-a thread 11 cut internally at eachend. g I V 1 Into it are screwed twospecial plugs 12,

having 'a concave endg ofthesame radius as 5 theball118 also having ahole 14; thru them which forms a steampassager w 5 C One. plug ispermai'iently screwed in then the ball 13 is put in which isfree to"roll= Y'Fhe'oth r plug 12 is then put iii piaeeand screwed up to aboutone eighth of an inch from the ball 13, this therefore permits the ball13 a movement of one eighth of an inch between the concave seats at theends of plugs 12. V 7 V The travel of the ball 13 may be adjusted V byturning plugs 12: r

To allow steam to pass from the cylinder into the piston head 1 theremay. be one hole at the top of piece 10 or a number of small I holes 15pitched diametrically as shown in Figure 4 may be used. I

In'my improvements the insideof piston head becomes a receiver or dome;which is an important feature, because when engines are linked up orworking at a high rate of expansion, the steam in this container is useduntil commencement of another stroke, producing the same efiect asincreased clearance. And. further in engines using superheated steam thepiston being'kept uniformlyhot prevents carbon deposit. 1 7 While I haveshown a preferred method of applying my invention I do not desire to belimited to the exact, form which I have here indicated as I am aware Iam entitled to such changes or variations as fall within the sco e ofthe appended claims.

he action of steam upon a piston head when fitted with my improvementsas follows When steam is admitted into the cylinder it goes thru thehole 14, blows ball 13 back against a concave seat, the steam then pamesthru the small holes 15 into the piston head cavities. a a

lVhen the piston head is nearlyfull it euters groove 7 thru the hole 6,then being confined between the packing rings 5 and the tongue pieces 8it slightly raises the piston head and piston rod to the top ofcylinder. Upon the return. strokethis action is re peated. y y

There is no exhaust except what steam escapes the packing rings or byworn condition or faulty workmanship. 1

The lifting pressure is calculated by the difference in projected areabetween the surfaces confined inside the packing rings and the tonguepieces.

The projected area at top must always be less than the bottom, theamountbeing regulated by the weight of piston head and by the workingpressure of the boiler.

Having thus described .my invention I c1a im:

1. The combination with a horizontal cylinder. of a piston headreciprocable therein, said head having a transverse bore therethrough. asingle double acting check valve loosely mounted in said bore, removablevalve seats mounted in the opposite ends of said bore, a transversepassage leading from the interior of said bore to the periphery of thehead, laterally spaced apart resilient packing rings set in theperiphery of the piston head and defining an annular channel around thepiston head,the aforesaid transverse passage opening into a segmentalgroove in said channel, said groove extending to about the verticalcenter, abutments mounted in said channel above said center and adjacentthe upper ends of the segmental groove.

2. In a pistonfor horizontal cylinders, a hollow piston head, acylindrical balancin chamber extending transversely through sai 'head,said chamber comprising a tubular sleeve threaded into the o posite.faces of and yielding tongues or abutments mounted in the space betweenthe packing lrings above the ends of the segmental groove atdiametrically opposite points of the circum ference of the piston, andatleast above the vertical center of the head, all as and for thepurposes specified. I i

Signed at Vancouver, Clarke County, State of Washington, this 1925.

DAVID L. MARTYN.

18 day of May,

